Solar Powered (fan) Fridge Roof Vent?

[James E Vining]

A few years ago I seen a Solar Powered Fan Fridge Roof vent, I cannot find it now nor did my search on here get any results I was looking for.
Supposedly this vent somehow detects fridge vent temperature and when it gets to a certain temp it turns on the fan to assist in pulling out hot air and it either has a battery that is recharged by solar panel or the solar panel just powers fan ( I assume previous over later)
I was curious if anyone has seen one of these or has used one?
I have to replace my fridge roof vent as mine was metal and the metal top cover somehow blew off I cannot find it anywhere, so was thinking a fan powered vent may be quite handy.

[HandyDan]

Camping World has them.  They are a Camco product and costs about $80.

[James E Vining]

 :)rotflmao  OMG I was just coming here to post that info, when i was looking up replacement Fridge roof vents I only got the Dometic Plastic covers then last night/ morning  depending on how you view it I found the Solar powered ones.

http://www.campingworld.com/shopping/item/solar-powered-rv-fridge-vent-system/47888